Sheet feeding apparatus



Feb 15, 1965 L. J. STREET ETAL 3,235,249

SHEET FEEDING APPARATUS Filed April l, 1965 2 Sheets-Sheet 1 INYINTo/(S LEsble JbHN .SI'REET' Gamez GAMES SAMUEL movLT Feb. 15, 1966 Filed April 1, 1965 L. J. STREET ETAL SHEET FEEDING APPARATUS 2 Sheets-Sheet 2 \I\VENTDKS f LesLlE JOHN STREET GEOR @E JAMES snmueh MOULT United States Patent C) j 3,235,249 SHEET' FEEDING APPARATUS Leslie .lohn Street, Long Ashton, near Bristol, and George James Samuel Moult, Bristol, England, assignors to Parhall` &` Sons Limited, Birmingham, England, a British company Filed Apr. 1, 1963, Ser. No. 269,245 iaims priority, application Great BritaimApr; 4, 1962,

12,380/62 7 Claims. (CL 271-12) This inventionrelates to sheet feeding apparatus, such as forl example apparatus for feeding sheets in the form of football pool coupons, bank cheques, punched cards or the like bearing encoded information for processing in a document sorting machine.

The invention has for its principal object to afford a reliable feed of successivev single sheets from a stack of sheets.

The invention consists of a single sheet feeding apparatus comprising sheet transporting means adapted for engaging the front face of the foremost sheet of a stack of sheets and transporting said sheet edgewise in a forward direction, a fixed head having a ported face in proximity tothe path of the rear face of the transported sheet with negativeiair pressure appliedto said` ports at intervals synchronised with the operation of the sheet transporting means so as to permit the traverse past the head ofthe foremost sheet and to retain temporarily onV the headany second sheet adhering to the formostsheet, and rejecting means synchronisedin operation'with the sheet transporting means and the fixed head and operating to drive` in reverse direction to that aforesaid any second sheet which has been retained on the fixed head.

In one` form of the aforesaid apparatus according to the invention the rejecting means consists of a continuously rotatable drum having ports, preferably in a larger diameter sector of its generally cylindrical face, and a negative air pressure applied to the interior of the drum, the ported part of said cylindrical face being exposed through the ported face of the fixed tank one in each revolution of the drum.

Conveniently the aforesaid sheet transporting means consists of at least one endless belt running in proximity to the ported face of the fixed head in the opposite direction to the adjacent part of the surface of said drum with ports in the belt through which is applied a negative air pressure serving intermittently to suck the forward marginal part of the front face of the foremost sheet on to the belt to abstract the foremost sheet from the stack and transport same past the fixed head.

One example of the practical realisation of the invention is described with reference to the accompanying drawings wherein:

FIGURE l is a side elevation of sheet feeding apparatus according to the invention,

FIGURE 2 is a longitudinal cross-section of the rejecting head embodied in FIGURE 1,

FIGURE 3 is a vertical cross-section on the line AA of FIGURE 2, and

FIGURE 4 is a vertical cross-section on the line BB of FIGURE 2, but with the moving parts 90 displaced to that shown in FIGURE 3.

The illustrated embodiment of the invention comprises a magazine 1t) for accommodating a stack 11 of paper sheets with the sheets disposed in parallel vertical planes also parallel with the plane of a feed gap between the forward and reverse running elements forming parts of sheet transporting and rejecting means respectively hereinafter described. Means is provided for urging the front face of the foremost sheet 12 of the stack into engagement with the forward running elements 13 of the sheet trans- 3,235,249 Patented Feb. 15, 1966 ice porting means; for example they magazine 1f) may consist` of an open-topped and open-front box-like holder resting on a conveyor belt 14 so that the conveyor urges the front face of the magazine 10 towards said forward running elements 13 as described in the commonly owned, copending United States application of StanleyV H. A. Thompson et al. Serial No. 228,942 filed October 8, 1962 for Document Processing Machines.

The sheet transporting means comprises two parallel running toothediendless rubber belts 13 passing over continuously driven toothed pulley wheels 27 so that the belts follow parallel triangular courses with their upward vertical runs definingone side of the feed gap. The belts are ported in longitudinally spaced apart regions and the said vertical runs move before respective hollow shoes 15 to which are applied a partial vacuum.

On theV opposite side of the feed gap to the vertical runs of the belts 13 is the ported (23) flat low friction face 16 of a fixedsheet rejecting head generally designated 17. Within the head 17 is disposed the rejected means comprising anend of a rotatably mounted shaft 18 keyed to a drum 19 having ports 20 in approximately one half off itsicircumference withanother part 2li of the circumference stepped inwardly to a lesser radius than that of the ported sector 22. The portedtsector 22 of thedrum projects through a window in the portedface 16 of the head 17 and reaches slightly beyond the plane of said face 16. The shaft 18 is continuously driven via a toothed pulley wheel 28 and toothed belt (not shown) in synchrony with the movement of the belts 13.

The ports 23 and 2i) in the face 16 of the rejecting head and periphery of the drum19 communicate through valve ports 24 and 2SV in the drum, to a vacuumsource (not shown).

Above the fixed head 17 the belts 13 coact with` idle rollers 26, serving to continue the feed of the sheets from the sphere of operation of the rejecting head 17 to reading and/ or sorting mechanism.

In operation a stack 11 of sheets is inserted edgewise on the floor of the magazine 10 with the vertical planes of the sheets parallel to the feed gap and the front face of the foremost sheet 12 urged into engagement with the upward runs of the ported belts 13. As the ported areas of the belts 13 reach the upper marginal part of the front face of the foremost sheet 12 the vacuum in the shoes 1S behind the belts 13 is communicated through the belt ports and serves to suck the foremost sheet 12 against the belts 13 whereby the sheet 12 is lifted from the stack and transported into the region of the fixed head 17. Shortly after the foremost sheet 12 has been gripped on the belts 13 the vacuum is applied (see FIGURE 4) through the valve ports 24 and 25 to the ports 23 in the face 16 of the fixed head and this serves to suck on to this face 16 any second or subsequent sheet that may be adhering to the foremost sheet 12, whilst allowing the first sheet to proceed in View of the low friction between two overlapping sheets. Due to the interval between the application of the vacuum to the belts 13 and to the fixed head ports 23, the fixed head releases for engagement by the belts, after clearance of the first sheet, any second sheet retained during the passage of a previous sheet. After the upper marginal part of the foremost sheet 12 has been transported past the fixed head and after the application of vacuum to the fixed head ports 23, the vacuum is then applied to the ports 20 in the .reverse running drum 19 with the result that the drum grips on its ported surface 22 any sheet retained on the fixed head face 16 and returns this sheet back towards the stack 11. One advantage of the stepped form of the cylindrical surface of the drum 19 is that it avoids unnecessary wearing engagement between the drum 19 and the sheets whilst the drum ports Ztl are outside the vicinity of the head face 16.

The phasing between the application of the partial vacuum to the xed head ports 23 and the drum ports 20,

and between these functions and the portsof the' belts` 13 can be varied to suit the grade of paper being handled and/or the speed of operation, for example by splining the shaft 18 so that the drum 19 and pulley 28 can be keyed at appropriate angular positions on the shaft.

To improve the separation of the sheets issuing from the stack an air nozzle 29 directs an air jet at right angles to the feed gap and between the stack 11 and the sheet rejecting head 17. The air liow can be derived from the output of a centrifuged fan (not shown) whose input provides the negative pressure for the shoes l5 and the head and drum ports 23 and 20.

It is to be appreciated that the above described ported belts 13 and ported drum 19 are not essential features of the invention since they can be replaced by equivalent elements adapted to frictionally engage the sheets at the appropriate periods in the sheet feeding cycle of operation of the apparatus.

We claim:

1. A single sheet feeding apparatus comprising sheet transporting means adapted for engaging the front face of the foremost sheet of a'stack of sheets and transporting said sheet edgewise in a forward direction, a xed head having a ported face in proximity to the path of the rear face of the transported sheet, means intermittently applying a negative air pressure t0 said ports at timed intervals which are so synchronised with the operation of the sheet transporting means in feeding said foremost sheet as to permit traverse of said foremost sheet past said head and to retain temporarily on the head any trailing second sheet adhering to the moving foremost sheet, and rejecting means disposed at said fixed head synchronised in operation with the sheet transporting means and the application of said negative pressure at said ports of the fixed head and operating to drive in reverse direction to that aforesaid any second sheet which has been retained on the fixed head, said rejecting means comprising a continuously rotatable drum the periphery whereof projects through the ported face of said head.

2. A single sheet feeding apparatus according to claim 1, wherein a sector of the periphery of the drum has ports in communication through the drum with a vacuum source.

3. A single sheet feeding apparatus according to claim 2, wherein the ported sector of the drum periphery is of larger radius than the remaining unported sector so that only the larger radius sector projects through the ported face of the head.

4. A single sheet feeding apparatus according to claim 2, or 4, wherein the connection of the vacuum source to the ported face of the head is controlled by valves opened and closed with rotation of the drum.

5. A single sheet feeding apparatus according to claim 1, incorporating means for varying the phasing of the connection of the negative air pressure'to the head ports, the engagement of the rejecting means with any second sheet, and the operation of the sheet transporting means.

6. A single sheet feeding apparatus according to claim 1, wherein said sheet transporting means comprises at least one continuously drivable endless beit having ports in a part of its length passing over a shoe connected to a vacuum source.

7. A single sheet feeding apparatus according to claim i, incorporating a nozzle for directing an air jet perpendicular to the path of the sheets as they approach said head.

References Cited by the Examiner UNITED STATES PATENTS 2,621,928 12/1952 Laurier 271--12 2,624,576 1/1953 Lautier 2714-12 2,804,974 9/1957 Noon. 2,936,170 S/1960 Herrick et al 271-12 3,067,998 12/1962 Cattorini et al. 271-'12 ROBERT B. REEVES, Primary Examiner.

RAPHAEL M. LUPO, Examiner. 

1. A SINGLE SHEET FEEDING APPARATUS COMPRISING SHEET TRANSPORTING MEANS ADAPTED TO ENGAGE THE FRONT FACE OF THE FOREMOST SHEET OF A STACK OF SHEETS AND TRANSPORTING SAID SHEET EDGEWISE IN A FORWARD DIRECTION, A FIXED HEAD HAVING A PORTED FACE IN PROXIMITY TO THE PATH OF THE REAR FACE OF THE TRANSPORTED SHEET, MEANS INTERMITTENLY APPLYING A NEGATIVE AIR PRESSURE TO SAID PORTS AT TIMED INTERVALS WHICH ARE SO SYNCHRONISED WITH THE OPERATION OF THE SHEET TRANSPORTING MEANS IN FEEDING SAID FOREMOST SHEET AS TO PERMIT TRAVERSE OF SAID FOREMOST SHEET PAST SAID HEAT AND TO RETAIN TEMPORARILY ON THE HEAD ANY TRAILING SECOND SHEET ADHERING TO THE MOVING FOREMOST SHEET, 